SIMULTANEOUS HPLC DETERMINATION OF CHOLESTEROL, ALPHA-TOCOPHEROL, RETINOL, RETINAL AND RETINOIC ACID IN SILICONE OILS USED AS VITREOUS SUBSTITUTES IN EYE SURGERY

A reverse phase high performance liquid chromatographic method for the simultaneous determination of cholesterol, alpha-tocopherol, retinol, retinal and retinoic acid in silicone oils, used as vitreous substitu tes in eye surgery, is reported. The mixture components are removed fr om the matrix with recoveries close to 97% by solid-phase extraction w ith silica cartridges and subsequently separated on a C-8 column, usin g two different mobile phases consisting of acetonitrile/ammonium acet ate and methanol/water that are passed sequentially. The compounds are detected by UV-Vis spectroscopy at two different wavelengths (210 and 350 nm) that are also set sequentially. The detection limits thus ach ieved range from 0.19 to 7.48 mu g mL(-1).